ESPRIT Method Research Articles

Optimally weighted ESPRIT for direction estimation

The Markov theory for solving perturbed systems of linear equations is applied to the ESPRIT method for direction estimation in array signal processing. The Markov-based ESPRIT estimates of the unknown directions are shown to be significantly more accurate than the commonly used least-squares ESPRIT estimates. Die Markoff Theorie zur Lösung von gestörten linearen Gleichungssystemen wird auf die ESPRIT Methode zur Richtungsschätzung in der Array-Signalverarbeitung angewendet. Es wird gezeigt, daβ die Markoff basierten ESPRIT Schätzungen unbekannter Richtungen signifikant bessere Genauigkeit aufweisen als die üblichen Least-Squares ESPRIT Schätzungen. La théorie de Markov pour la résolution de systèmes d'èquations linèaires perturbèes est appliquèe à la mèthode ESPRIT d'estimation de direction en traitement de signal de réseau. Les etimèes ESPRIT markoviennes des directions inconnues sont montrées être significativement plus précises que les estimées ESPRIT aux moindres carrés communément utilisées.

Effect of spatial smoothing on the performance of subspace methods in the presence of array model errors

In this paper, the effect of spatial smoothing (Forward smoothing and Forward-Backward smoothing) on the performance of unweighted and weighted subspace methods in the presence of Array Model errors for Direction-Of-Arrival (DOA) estimation is studied. Theoretical expressions for the Mean Squared Error (MSE) in DOA are obtained, based on a common framework of analysis. For weighted subspace methods, optimal weighting matrices are presented which minimize the MSE in DOA. Two typical errors, Random errors and Gain and Phase errors are considered as examples for illustration. Simulations are carried out to substantiate the theory developed. For the cases considered, smoothing improves the performance of ESPRIT and Minimum-Norm method while it is not so for MUSIC. Forward-Backward smoothing improves the performance of all methods compared to that of Forward smoothing.

Direction finding using ESPRIT with interpolated arrays

The technique of interpolated arrays is applied to ESPRIT-type direction finding methods. The resulting method uses sensor arrays with an arbitrary configuration, thus eliminating the basic restrictive requirement of ESPRIT for two (or more) identical arrays. This approach allows for resolving D+1, while the original ESPRIT method requires at least 2D sensors. Moreover, it is shown that while ESPRIT performs poorly for signals propagating in parallel (or close to parallel) with the array displacement vector, the advocated technique does not exhibit such weakness. Finally, using two subarrays, ESPRIT cannot resolve azimuth and elevation even when the sensors are not collinear. However, the interpolated ESPRIT procedure resolves azimuth and elevation using only a single array. The performance of the original ESPRIT when the sensor locations are perturbed is also discussed and illustrated numerically. >

Parallel VLSI matrix pencil algorithm for high resolution direction finding

Algorithms to find the directions of arrival (DOAs) of multiple signals from measurements on an array of antenna doublets (ESPRIT method) and their parallel VLSI implementation are discussed. In particular, algorithms that allow large-scale pipelining and use only robust, unitary transformations are identified. This problem is solved by a matrix pencil approach in which the generalized eigenvalues of a pair of data matrices are determined. A modified Stewart Jacobi approach is used for which convergence is improved and parameter computations are simplified. The resulting architecture is a two-layer Jacobi array that can handle all the subproblems: two QR factorizations, two SVDs, and a single generalized Schur decomposition. The mapping of the subproblems on a single parallel array of CORDIC processors is considered.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Coherent wide-band ESPRIT method for directions-of-arrival estimation of multiple wide-band sources

A strategy extending the coherent signal-subspace method (CSM) is proposed for estimating directions of arrival of multiple wideband sources. The proposed method, coherent wideband ESPRIT, extends the ESPRIT algorithm to a framework based on the CSM. A simulation example is provided to illustrate the effectiveness of the proposed method.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>